DNS
THE CERTIFICATE BEHIND THE CONNECTION

TLS certificate checker.

Inspect SSL/TLS certificates for any public domain or subdomain.

Checks HTTPS on port 443, including subject alternative names, validity dates and the presented chain.

SSL certificate

TLSv1.3

groupon.com · 104.18.12.36:443

Verified

Certificate chain, hostname and dates verified using this server’s CA store.

Subject
CN=groupon.com
Issuer
C=US O=Google Trust Services CN=WR1
Valid from
2026-09-27T10:01:26+00:00
Expires
2026-12-26T10:59:09+00:00
Days remaining
70
Serial (hex)
27F901CF7864A6A513ABE677BF36A930
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:groupon.com, DNS:cosai.groupon.com, DNS:*.cosai.groupon.com

SHA-256 fingerprint

0E:68:CA:8C:84:5F:A6:34:12:DE:EF:F9:7C:D2:D9:47:E0:FD:5C:E7:A5:2C:FF:56:6F:B7:3B:72:04:17:07:CB
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
B0:5B:E9:C1:1E:97:23:38:43:06:FE:6B:D6:84:99:D5:AF:72:42:FC
authorityKeyIdentifier
66:69:49:D4:DE:2A:9C:91:03:CF:89:0E:24:B8:0E:30:03:6E:88:2E
authorityInfoAccess
CA Issuers - URI:http://i.pki.goog/wr1.crt
subjectAltName
DNS:groupon.com, DNS:cosai.groupon.com, DNS:*.cosai.groupon.com
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://c.pki.goog/wr1/mKooUibXfhE.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : D7:6D:7D:10:D1:A7:F5:77:C2:C7:E9:5F:D7:00:BF:F9: 82:C9:33:5A:65:E1:D0:B3:01:73:17:C0:C8:C5:69:77 Timestamp : Sep 27 11:01:27.302 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:DF:22:A8:7B:09:01:51:DA:CE:19:96: 15:76:1E:8D:B8:E1:80:DC:10:AE:E6:66:A2:B0:F3:D4: 30:92:E1:08:E7:02:21:00:C0:4C:78:85:46:0E:AD:AE: 18:B7:71:42:FA:B8:BC:D4:DC:0D:FB:CD:B3:9B:AE:C9: E3:24:3F:D2:C8:6A:98:90 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : CB:38:F7:15:89:7C:84:A1:44:5F:5B:C1:DD:FB:C9:6E: F2:9A:59:CD:47:0A:69:05:85:B0:CB:14:C3:14:58:E7 Timestamp : Sep 27 11:01:27.288 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:44:02:20:40:CD:AD:62:23:E2:BA:11:53:2A:1A:94: ED:8B:55:98:FF:7B:68:40:CC:7A:FA:F8:3B:7D:9F:03: 17:35:03:E1:02:20:5D:7D:48:C9:E5:39:6F:1C:6C:8F: 2B:3C:B3:8F:1F:A5:74:0A:74:87:78:6C:36:B8:12:6E: 0F:80:4F:F3:BB:48
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_128_GCM_SHA256 · Checked 2026-10-17T01:27:27+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=US O=Google Trust Services CN=WR1
Issuer
C=US O=Google Trust Services LLC CN=GTS Root R1
Valid from
2023-12-13T09:00:00+00:00
Expires
2029-02-20T14:00:00+00:00
Days remaining
857
Serial (hex)
7FD9E2C2D2048A0474B627A26D0868A7
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

B1:0B:6F:00:E6:09:50:9E:87:00:F6:D3:46:87:A2:BF:CE:38:EA:05:A8:FD:F1:CD:C4:0C:3A:2A:0D:0D:0E:45
Certificate extensions & PEM
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication, TLS Web Client Authentication
basicConstraints
CA:TRUE, pathlen:0
subjectKeyIdentifier
66:69:49:D4:DE:2A:9C:91:03:CF:89:0E:24:B8:0E:30:03:6E:88:2E
authorityKeyIdentifier
E4:AF:2B:26:71:1A:2B:48:27:85:2F:52:66:2C:EF:F0:89:13:71:3E
authorityInfoAccess
CA Issuers - URI:http://i.pki.goog/r1.crt
crlDistributionPoints
Full Name: URI:http://c.pki.goog/r/r1.crl
certificatePolicies
Policy: 2.23.140.1.2.1
-----BEGIN CERTIFICATE-----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=
-----END CERTIFICATE-----

Chain certificate 2

Subject
C=US O=Google Trust Services LLC CN=GTS Root R1
Issuer
C=BE O=GlobalSign nv-sa OU=Root CA CN=GlobalSign Root CA
Valid from
2020-06-19T00:00:42+00:00
Expires
2028-01-28T00:00:42+00:00
Days remaining
467
Serial (hex)
77BD0D6CDB36F91AEA210FC4F058D30D
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

3E:E0:27:8D:F7:1F:A3:C1:25:C4:CD:48:7F:01:D7:74:69:4E:6F:C5:7E:0C:D9:4C:24:EF:D7:69:13:39:18:E5
Certificate extensions & PEM
keyUsage
Digital Signature, Certificate Sign, CRL Sign
basicConstraints
CA:TRUE
subjectKeyIdentifier
E4:AF:2B:26:71:1A:2B:48:27:85:2F:52:66:2C:EF:F0:89:13:71:3E
authorityKeyIdentifier
60:7B:66:1A:45:0D:97:CA:89:50:2F:7D:04:CD:34:A8:FF:FC:FD:4B
authorityInfoAccess
OCSP - URI:http://ocsp.pki.goog/gsr1 CA Issuers - URI:http://pki.goog/gsr1/gsr1.crt
crlDistributionPoints
Full Name: URI:http://crl.pki.goog/gsr1/gsr1.crl
certificatePolicies
Policy: 2.23.140.1.2.1 Policy: 2.23.140.1.2.2 Policy: 1.3.6.1.4.1.11129.2.5.3.2 Policy: 1.3.6.1.4.1.11129.2.5.3.3
-----BEGIN CERTIFICATE-----
MIIFYjCCBEqgAwIBAgIQd70NbNs2+RrqIQ/E8FjTDTANBgkqhkiG9w0BAQsFADBX
MQswCQYDVQQGEwJCRTEZMBcGA1UEChMQR2xvYmFsU2lnbiBudi1zYTEQMA4GA1UE
CxMHUm9vdCBDQTEbMBkGA1UEAxMSR2xvYmFsU2lnbiBSb290IENBMB4XDTIwMDYx
OTAwMDA0MloXDTI4MDEyODAwMDA0MlowRzELMAkGA1UEBhMCVVMxIjAgBgNVBAoT
GUdvb2dsZSBUcnVzdCBTZXJ2aWNlcyBMTEMxFDASBgNVBAMTC0dUUyBSb290IFIx
MIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAthECix7joXebO9y/lD63
ladAPKH9gvl9MgaCcfb2jH/76Nu8ai6Xl6OMS/kr9rH5zoQdsfnFl97vufKj6bwS
iV6nqlKr+CMny6SxnGPb15l+8Ape62im9MZaRw1NEDPjTrETo8gYbEvs/AmQ351k
KSUjB6G00j0uYODP0gmHu81I8E3CwnqIiru6z1kZ1q+PsAewnjHxgsHA3y6mbWwZ
DrXYfiYaRQM9sHmklCitD38m5agI/pboPGiUU+6DOogrFZYJsuB6jC511pzrp1Zk
j5ZPaK49l8KEj8C8QMALXL32h7M1bKwYUH+E4EzNktMg6TO8UpmvMrUpsyUqtEj5
cuHKZPfmghCN6J3Cioj6OGaK/GP5Afl4/Xtcd/p2h/rs37EOeZVXtL0m79YB0esW
CruOC7XFxYpVq9Os6pFLKcwZpDIlTirxZUTQAs6qzkm06p98g7BAe+dDq6dso499
iYH6TKX/1Y7DzkvgtdizjkXPdsDtQCv9Uw+wp9U7DbGKogPeMa3Md+pvez7W35Ei
Eua++tgy/BBjFFFy3l3WFpO9KWgz7zpm7AeKJt8T11dleCfeXkkUAKIAf5qoIbap
sZWwpbkNFhHax2xIPEDgfg1azVY80ZcFuctL7TlLnMQ/0lUTbiSw1nH69MG6zO0b
9f6BQdgAmD06yK56mDcYBZUCAwEAAaOCATgwggE0MA4GA1UdDwEB/wQEAwIBhjAP
BgNVHRMBAf8EBTADAQH/MB0GA1UdDgQWBBTkrysmcRorSCeFL1JmLO/wiRNxPjAf
BgNVHSMEGDAWgBRge2YaRQ2XyolQL30EzTSo//z9SzBgBggrBgEFBQcBAQRUMFIw
JQYIKwYBBQUHMAGGGWh0dHA6Ly9vY3NwLnBraS5nb29nL2dzcjEwKQYIKwYBBQUH
MAKGHWh0dHA6Ly9wa2kuZ29vZy9nc3IxL2dzcjEuY3J0MDIGA1UdHwQrMCkwJ6Al
oCOGIWh0dHA6Ly9jcmwucGtpLmdvb2cvZ3NyMS9nc3IxLmNybDA7BgNVHSAENDAy
MAgGBmeBDAECATAIBgZngQwBAgIwDQYLKwYBBAHWeQIFAwIwDQYLKwYBBAHWeQIF
AwMwDQYJKoZIhvcNAQELBQADggEBADSkHrEoo9C0dhemMXoh6dFSPsjbdBZBiLg9
NR3t5P+T4Vxfq7vqfM/b5A3Ri1fyJm9bvhdGaJQ3b2t6yMAYN/olUazsaL+yyEn9
WprKASOshIArAoyZl+tJaox118fessmXn1hIVw41oeQa1v1vg4Fv74zPl6/AhSrw
9U5pCZEt4Wi4wStz6dTZ/CLANx8LZh1J7QJVj2fhMtfTJr9w4z30Z209fOU0iOMy
+qduBmpvvYuR7hZL6Dupszfnw0Skfths18dG9ZKb59UhvmaSGZRVbNQpsg3BZlvi
d0lIKO2d1xozclOzgjXPYovJJIultzkMu34qQb9Sz/yilrbCgj8=
-----END CERTIFICATE-----

One endpoint on port 443. Server-presented chain; no revocation, OCSP, CT or full TLS security scan.

View certificate JSON

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